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United States Patent |
5,648,101
|
Tawashi
|
July 15, 1997
|
Drug delivery of nitric oxide
Abstract
A method of delivering NO gas to a desired situs on or in the body of a
sentient animal, e.g. humans, comprising combining and causing to react a
soluble reducing salt, preferably ferrous sulfate, and a nitrite,
preferably sodium nitrite, as reactants in the presence of moisture in
situ at or adjacent such situs. Means for such delivery include
compositions such as tablets, capsules, ointments, creams, lotions, and
sprays containing mixtures of particles or granules of the two reactants,
and transdermal patches and osmotic pumps for combining solutions of
reactant or reactants in situ.
Inventors:
|
Tawashi; Rashad (66 Hyde Park, Beaconsfield, Quebec, CA)
|
Appl. No.:
|
338664 |
Filed:
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November 14, 1994 |
Current U.S. Class: |
424/718; 424/400; 424/449; 424/451; 424/463; 424/464; 424/474; 424/475; 424/484; 424/486; 424/489; 424/490; 424/497; 424/501; 424/648; 424/DIG.15; 514/929; 514/966; 514/967; 514/968; 514/969 |
Intern'l Class: |
A61K 033/00; A61K 033/26; A61K 009/02; A61K 009/14; DIG. 15 |
Field of Search: |
424/718,400,445-446,449,451,463-464,474-475,484-486,488,491,493,496-502,648
423/405
514/929,966,967,968,969
604/19,27
623/12
|
References Cited
U.S. Patent Documents
5234956 | Aug., 1993 | Lipton | 514/724.
|
5583101 | Dec., 1996 | Stamler et al. | 514/2.
|
Other References
Johnson, III. Gerald et al., "Cardioprotective Effects of Acidified Sodium
nitrite in myocardial ischemia with reperfusion", The Journal of
Pharmacology and Experimental Therapeutics, vol. 252(1), pp. 35-41, 1990.
Cotton, F. Albert et al., Advanced Inorganic Chemistry, 5th ed., John Wiley
& Sons, New York, 1988, pp. 321-323.
Biological Abstracts 89(9):96652, 1990; abstracting, Johnson et al.,
"Cardioprotective effects of acidified sodium nitrite in myocardial
ischemia with reperfusion," J. Pharmacol. Exp. Ther., vol. 252(1), 1990,
pp. 35-41.
Martindale The Extra Pharmacopoeia, (Reynolds et al. eds.), 13th ed., The
Pharmaceutical Press, London, 1993, pp. 1220-1221.
The Merck Index, 10th ed., Merck & Co., Inc., Rahway (NJ), 1983, pp.
330-331.
|
Primary Examiner: Pak; John
Attorney, Agent or Firm: Leavitt; Samson B., Leavitt; Michael A.
Claims
I claim:
1. A method of delivering NO gas to a desired situs on or in the body of a
sentient animal comprising combining, and causing to react, substantially
molecularly equivalent amounts of ferrous sulfate and an organic or
inorganic nitrite as reactants with moisture present at or adjacent said
situs.
2. A method according to claim 1 employing sodium nitrite as the nitrite.
3. A method according to claim 2 wherein said reactants are delivered to or
adjacent said situs in the form of a mixture of discrete granules of each
reactant.
4. A method according to claim 3 wherein said granules are made by
granulation in admixture with polyvinyl pyrrolidone and citric acid.
5. A method according to claim 4 wherein said granules are delivered in the
form of a tablet or capsule containing multiple discrete ferrous sulfate
and sodium nitrite granules.
6. A method according to claim 5 wherein said tablet or capsule carries an
enteric coating.
7. A method according to claim 4 wherein said granules are topically
delivered in an anhydrous hydrophilic base as an ointment, lotion, cream
or suppository.
8. A method according to claim 2 wherein said reactants are delivered to or
adjacent said situs in the form of a vaporous or gaseous mixture or
dispersion of said reactants in finely divided form supported on discrete
inert finely divided solid particles.
9. A method according to claim 8 wherein said solid particles comprise
lactose crystals, spores, pollen grains or starch grains.
10. A method according to claim 2 employing an adhesive transdermal patch
impregnated with dry particles of ferrous sulfate and wetted with an
aqueous solution of organic or inorganic nitrite.
11. A method according to claim 2 employing an adhesive transdermal patch
impregnated with dry particles of organic or inorganic nitrite and wetted
with an aqueous solution of ferrous sulfate.
12. A method according to claim 2 employing osmotic pump technology wherein
a first osmotic pump containing an aqueous solution of ferrous sulfate and
a second osmotic pump containing a substantially equimolar aqueous
solution of organic or inorganic nitrite are inter-connected by tubing to
a common cannula catheter assembly leading to and ending at or adjacent
said situs of treatment and constant delivery of the mixture of the
aqueous solutions and NO gas through said cannula catheter assembly is
initiated by implantation of the pumps in the body of said animal or by
immersion of the pumps in an aqueous physiological solution.
13. A method according to claim 2 employing osmotic pump technology wherein
a first osmotic pump containing an aqueous solution of organic or
inorganic nitrite and a second osmotic pump containing a substantially
equimolar aqueous solution of ferrous sulfate are inter-connected by
tubing to a common cannula catheter assembly leading to and ending at or
adjacent said situs of treatment and constant delivery of the mixture of
the aqueous solutions and NO gas through said cannula catheter assembly is
initiated by implantation of the pumps in the body of said animal or by
immersion of the pumps in an aqueous physiological solution.
Description
FIELD OF THE INVENTION
This invention relates to the drug delivery of nitric oxide (NO), and more
particularly to methods, means and compositions for the in situ production
and delivery of NO to a desired situ on or in the body of a sentient
animal, especially humans.
BACKGROUND OF THE INVENTION
In December 1992 Science magazine named NO the molecule of the year. In the
atmosphere nitric oxide is a noxious chemical but in the biological system
in controlled small doses it is extraordinarily beneficial. It helps to
maintain blood pressure, dilate blood vessels, help kill foreign invaders
in the immune response and is a major biochemical mediator of penile
erection and probably a biochemical component of long term memory. These
are just a few of the many roles which are just beginning to be discovered
and have been documented in the scientific literature in the last 5 years.
NO is synthesized from the amino acid L-arginine by the enzyme NO synthase.
The release of NO via this enzyme has other pathological or biological
consequences including pathological vasodilation and tissue damage. The
formation of NO by this enzyme in vascular endothelial cells opened up
what can be considered a new era of biomedical and clinical application
research. NO released from the endothelial cells is indistinguishable from
EDRF (The endothelial derived relaxation factor) in terms of biological
activity, stability and susceptibility to inhibitors and promoters. There
is available evidence indicating that the cardiovascular system is in a
state of constant active vasodilation depending on the generation of NO.
Indeed NO can be considered the endogenous vasodilator. Decreased
synthesis of NO may contribute to the origin of conditions such as
atherosclerosis and hypertension. Nitro vasodilators that have been
clinically used the last 100 years and are still widely used in angina
pectoris, congestive heart failure, hypertensive emergencies, pulmonary
hypertension, etc. are acting through the formation of NO.
Biochemical experimentation has shown that the nitro vasodilator and NO act
by activating the soluble guanylate cyclase and it is widely accepted that
this activation and the consequent increase in cyclic GMP
(guanosine-5',5'-cyclic phosphoric acid) levels induces a sequence of
protein phosphorylation associated with smooth muscle relaxation.
Nitrovasodilators also generate NO in non-enzymatic reaction, and this
leads to the stimulation of soluble guanylate cyclase. The metabolism of
nitroglycerin, for example and other organic nitrates by denitration leads
to the formation of nitrites which subsequently undergoes
biotransformation to generate vasoactive intermediates such as
S-nitroso-thiols and nitric oxide. Direct evidence has been established
for nitric oxide formation from GTN (glyceryl trinitrate, nitroglycerin)
during incubation with intact bovine pulmonary artery. This transformation
has been measured chemically and is dependent on incubation time. Nitric
oxide provokes vaso-dilatation, and inhibits platelet aggregation. It is
involved in increased cerebral cortical blood flow, following the
stimulation of nucleus basalis of Heynert in anasthetized rats. Endogenous
NO acts as a mediator of gastric mucosal vaso-dilatation. It does not
directly modulate the acid secretory response but makes a substantial
contribution to the mucosal vaso-dilatation associated with the
stimulation of gastric acid secretion. It also mediates estrogen-induced
increases in uterine blood flow. The observed vaso-dilatation can be
antagonized by the intra-arterial administration of nitric synthase
inhibitor L-nitro arginine methyl ester.
Inhaled NO is a selective pulmonary vaso-dilator that can prevent
thromboxane-induced pulmonary hypertension during the heparin protamine
reaction and does so without causing systemic vasodilation. In biological
media NO is very active in a very small concentration. It reacts with
O.sub.2 to produce NO.sub.2 which then forms NO.sub.2 - and NO.sub.3 - in
neutral aqueous solutions according to the following equations:
2NO+O.sub.2 .fwdarw.2NO.sub.2 I
then
2NO.sub.2 +H.sub.2 O.fwdarw.NO.sub.2 -+2H.sup.+ +NO-.sub.3.II
Neither NO-.sub.2 nor NO-.sub.3 as their sodium salts cause any reaction to
vascular strips at a concentration below 10 uMol. The exact physiological
stimuli for the generation of NO are not fully understood but the
pulsatile flow and shear stress seem to be the main determinants.
NO has a great potential to be applied and used clinically in the treatment
of a variety of diseases and can offer a better substitute for a wide
range of commercially available vasoactive drugs. This could be realized
only if a suitable delivery system is designed for NO administration.
Today these systems do not exist and there is a need for the development
of these systems. All of the results that have been generated so far were
obtained indirectly either by working with NO synthase inhibitors or by
delivering NO as Prodrug (organic nitric oxide donors). The authentic
bioactive molecule has never been formulated in a convenient delivery
system having the capability of targeting and preserving the integrity of
nitric oxide molecule. The development and the optimization of such
systems is of paramount significance for the use of NO in therapeutics.
Nitric oxide NO, is a colorless gas with a boiling point of -151.7.degree.
C., melting point of -163.degree. C. and density of the liquid of 1.269 at
boiling point. The NO molecule contains an odd number of electrons. It is
soluble in water, 4.7 parts per 100 parts volume per volume at 20.degree.
C. and 1 atmosphere. NO reacts readily with oxygen to form brown ntirogen
dioxide. Under physiological conditions, nitric oxide can be
interconverted to different redox forms with different distinctive
chemistries. These forms are NO, NO.sup.+ and NO.sup.-. Current research
indicates that nitrovasodilators carry out their physiological functions
by releasing NO (neutral nitric oxide). It is to be noted that the
biological half life of this active molecule depends critically on the
concentration of the reactants used and on the initial concentration of
nitric oxide formed.
OBJECTS OF THE INVENTION
It is an object of this invention to provide methods for the in situ
production and delivery of NO to a desired situs on or in the body of a
sentient animal, especially humans. Another object is to formulate the
authentic proactive NO molecule in a convenient delivery system having the
capability of targeting and preserving the integrity of the NO molecule. A
further object of the invention is to provide such a delivery system which
is easy to operate, economical, using readily available materials, and
with dispatch. Other objects of the invention include the provision of
compositions, means and devices for carrying out such methods and systems.
Other objects and advantages will appear as the description proceeds.
SUMMARY OF THE INVENTION
In accordance with certain of its preferred aspects, this invention
comprises the provision of a composition adapted to release or liberate NO
gas at or adjacent a desired situs on or in the body of a sentient animal,
especially humans, comprising substantially molecularly equivalent amounts
of the preferred ferrous sulfate or equivalent water soluble biocompatible
reducing agent or mixture thereof such as ferrous chloride, or cuprous
sulfate or chloride or the like, and the preferred sodium nitrite, or
equivalent water soluble organic or inorganic nitrite such as generally
alkali metal and lower alkanol nitrites including potassium, ethyl, amyl,
isoamyl and octyl nitrites, erythritol trinitrite and the like, as
reactants productive of NO gas in the presence of moisture.
The invention also comprises methods and means for delivering the
compositions of this invention and/or NO gas at or adjacent the desired
situs on or in the body of a sentient animal.
The following description of the invention is, for the sake of simplicity,
reduction of proliferation of paperwork, excessive expansion of obvious
alterations, confusion and the like, concerned with the use of ferrous
sulfate and sodium nitrite as the preferred reactants.
DETAILED DESCRIPTION OF THE INVENTION
Bearing in mind the unusual physico-chemical and fundamental properties of
the NO molecule, this invention provides a novel technology for the
administration of this bioactive gas through the following means:
1) Development of an oral system for gastro-intestinal delivery (tablet and
capsule).
2) Development of local enhanced topical delivery system (LETDS) such as
ointment, suppository and patch.
3) Metered dose inhaler for pulmonary delivery
4) Development of a system of controlled constant rate delivery of NO using
osmotic pumping.
The performance of pure NO generated from these delivery systems for a
variety of functional target organs or systems depends on the redox state
of this molecule. Being an unstable molecule and having a high chemical
activity and short half life (of about 30 seconds), it requires
unprecedented precautions in formulation and administration. The charge
and neutrality of NO facilitates its diffusibility in aqueous media and
across the cell membrane. The present invention establishes with certainty
the delivery of NO gas to specific sites or organs or for a specific
systemic action and guarantees the control of the thermodynamic and
kinetic parameters of this reaction between ferrous sulfate and sodium
nitrite in the presence of moisture at the micro and nanomol level.
Ferrous sulfate acts herein not only as a reducing agent but as stabilizer
for NO, by delaying the action of hemoglobin as an NO scavenger. Ferrous
sulfate used in the reaction and which appears in the different
formulations is FeSO4, 7H.sub.2 O. It dissolves 1 part in 1.5 parts of
water at 15.degree. C. It has a molecular weight of 278. Sodium nitrite
(Na NO2) on the other hand, has a molecular weight of 69, and the reaction
between one mole of ferrous sulfate and one mole of sodium nitrite gives
one mole of nitric oxide, NO. This means that the proportion of ferrous
sulphate to sodium nitrite is about 4:1 weight/weight.
Stability of NO is maximized in presence of acid. The following equations
describe the chemical reaction in presence of acid and moisture.
2FeSO.sub.4 +2NaNO.sub.2 +C.sub.6 H.sub.8 O.sub.7 (ctiric
acid)+H2O.fwdarw.2NaH SO.sub.4 +Fe(OH).sub.3 +FeC.sub.6 H.sub.5 O.sub.7
+2NO III
In absence of acid the following reaction is obtained:
3FeSO.sub.4 +3NaNO.sub.2 +3H.sub.2 O.fwdarw.Fe.sub.2 (SO.sub.4).sub.3
+3NO+Fe(OH).sub.3 +3NaOH IV
The present invention encompasses the matter hereafter described and the
methods of preparation, for the following fields:
1--Gastroenterology/Endoscopy
Nitric oxide is a potent neurotransmitter mediating the relaxation of
sphincter muscles. This will have a significant application in
gastroenterology and endoscopy. Nitric oxide tablet, capsule, simple or
enteric will deliver NO to specific site without systemic effect. The
topical application of NO cream, ointment, suppository or transdermal
patch will have a significant application in the treatment of conditions
associated with anal fissures, some types of constipation, certain skin
conditions and the like.
2--Pulmonary Hypertension
Pulmonary hypertension is a disease of unknown origin, with higher
incidence among young women. It is characterized by vasoconstriction and
high blood pressure in pulmonary arteries which is controlled or inhibited
by the use of NO generated by chemical reaction between ferrous sulfate
and sodium nitrite in dry powder inhaler (DPI) or in aerosol form as
metered dose inhaler (MDI). The reaction will take place only in the lung
where moisture is present. The risks of inhaled NO will be eliminated
because an exact dose could be delivered in pulses, and for a short
contact time. Moreover the risks of NO oxidation involved in mechanical
ventilation using the NO gas is minimized.
3--Nitrovasodilators
In the cardiovascular system the release of NO acts as a general adaptive
mechanism where the vascular endothelium responds to changes in its
environment and regulates blood flow and blood pressure through an action
on the vascular smooth muscle. In addition NO regulates the interaction
between the endothelium platelets and probably blood borne cells. A prime
advantage of NO over nitro-vasodilators like nitroglycerin, sodium
nitrite, iso-sorbide dinitrate and penta erythritol tetranitrate, is that
the authentic NO drug molecule is directly delivered. The risk of varied
response associated with oral and transdermal delivery and the risks of
cutaneous metabolism are eliminated. There is less of a chance of over or
under dosage with this system in addition to a higher degree of
reproducibility and less side effects. Available information indicates
that the relation between nitroglycerin plasma concentration and
anti-anginal effect has not been well characterized. Experienced
investigators raised many questions about the extent of cutaneous
metabolism of GTN. Results available indicate clearly that organic
nitrates used as vasodilators must undergo biotransformation to NO before
vasodilatation can occur and that the mechanism of organic tolerance
involves decreased formation of NO. The use of the osmotic pumping
technique for the delivery of a constant rate of NO is more effective and
safer than the use of intravenously administered sodium nitroprusside. The
development of this NO delivery technology enables administration of the
exact dose, establish dose response relationship, monitor the hemodynamic
activity, and adjust and control the administered dose. NO will act not
only as vasodilator but increases the permeability of the blood brain
barrier to allow nerve growth factors and other important neurotrophic
agents to reach their target cells. Topical NO delivery will be the
treatment of choice for Reynaud's phenomenon, where capillary
vasoconstriction is the underlying cause.
4--Vaso-Active NO in Male Impotence
The use of vaso-active drugs is increasing in urology clinics worldwide.
These drugs have been formulated and introduced for auto-injection. Their
action as a single active component or as a mixture is not certain in all
patients. The present development of NO delivery by the transdermal or
transuretheral route is more effective and will eliminate risks and
inconveniences associated with the intracavernous injection of papaverine
or PGEI (prostaglandin E1) or their cocktails. The ability of the patient
to terminate the medication if needed by removing the transdermal device,
in addition to patient acceptance, is an obvious advantage.
For the preparation of granules, 1 part of ferrous sulfate powder, mixed
with about 0.25 to 15, preferably about 0.25 to 1.5, parts of a water
soluble conventional filler such as xylitol, sorbitol, lactose or the
like, and preferably about 0.2 to 0.5 parts of water soluble organic acid,
preferably citric acid, is granulated with about 0.1 to 1, preferably 0.2
to 1, part of a water soluble granulating or binding agent, preferably
polyvinyl pyrrolidone, in the form of alcoholic solution (e.g. 5-15%
conc.), dried at elevated temperatures, e.g. about 40.degree. C. to
70.degree. C. for about 5 to 20 hours, as in a hot air oven and sieved,
e.g. through a sieve No. 40 to 60.
The sodium nitrite granules are prepared in the same manner with the same
materials except for omission of the organic (citric) acid and with about
0.25 parts of sodium nitrite instead of 1 part of ferrous sulfate and then
thoroughly mixed with about equal amounts of the ferrous sulfate granules.
Capsules are prepared simply by charging the mixed granules into hard
gelatin capsules. The filled capsules disintegrate in water and liberate
NO in about 5 to 15 minutes.
Tablets are prepared by mixing 1 part of the mixed granules with about 0.01
to 0.1 part of a mold lubricant and release (anti-adhesive) agent such as
polyethylene glycol (PEG) 6,000 and compressed into tablets which dissolve
completely within about 12-15 minutes in water liberating NO as
effervescent tablets.
The tablets and the capsules prepared as above are if desired coated
enterically in known manner in order to liberate NO in the intestine using
illustratively formulation No. 5 below. Coating is carried out in a
coating pan. The enteric coated tablets and capsules resist disintegration
in artificial gastric juice for 2 hours, but when placed in artificial
intestinal juice, they disintegrate within 20 min. Tablets and capsules
simple or enteric coating are intended to deliver NO for site specific
action in the gastro-intestinal tract.
Examples (formulations) 1-5 below illustrate the procedures and materials
for preparing the tablets, capsules and enteric coatings thereof according
to this invention.
For topical delivery, ointment, cream, lotion, suppository or transdermal
patch systems are used. Except for the transdermal patch system, such
topical delivery systems employ ferrous sulfate and sodium nitrite
granules prepared as described above. One part of a 1:1 mixture of the two
types of reactant granules is incorporated into about 4 to 40 parts of a
conventional hydrophilic base or carrier such as one or a mixture of PEG's
ranging from 400 to 6,000 M.W., the higher molecular weight PEG's
averaging over about 2,200 M.W. being relatively more solid for use in
suppositories. Examples (formulations) 6-8 below illustrate procedures and
materials for preparing the ointments, creams, lotions and suppositories
according to this invention. It will be understood that in general
sufficient hydrophilic base of the requisite viscosity is employed to
provide the desired degree of consistency, spreadability or solidity in
preparing the ointments, creams, lotions and suppositories.
The transdermal patch system is similar to the commercially available
nitroglycerin or scopolamine patches applied once or twice weekly. Unlike
these TTS (transdermal therapeutic systems), the present system is
designed to be applied to the skin to deliver NO for a short period of
time not exceeding 1 hour. It is intended to deliver NO to the site where
it is applied and not to produce systemic effects. The active surface area
is about 1-4 cm.sup.2. The total amount of ferrous sulfate per patch is
about 0.025-0.050 mM of ferrous sulfate per cm.sup.2. This ferrous sulfate
is present in a multi-layer macroporous or foraminous gauze or cellulosic
matrix. The ferrous sulfate could be present with an equal amount of
citric acid. Before applying to the skin, sodium nitrite (concentration of
1M in water) is added to the active area of the patch in a quantity of
about 50 to 100 microliter. The amount of sodium nitrite added and the
amount of ferrous sulfate on the patch decide the dose of NO produced. The
pressure sensitive self adhesive membrane has a backing layer of gas
impermeable film, e.g. polyethylene, to prevent the loss of NO.
Examples (formulations) 9 and 10 below further illustrate the procedures
and materials for preparing transdermal patches according to this
invention.
For delivery of NO by dry power inhalation or aerosol, the ferrous sulfate
and sodium nitrite in finely divided form (particles or granules) are
deposited on finely divided discrete inert finely divided carrier
particles to permit delivery in the form of an airborne, vaporous or
gaseous dispersion. For this purpose, the carrier particles should be
smaller than about 100 micrometers to as low as about 3-5 micro meters,
and the deposited reactants of similar small size or even molecular as
deposited for example by precipitation from an aqueous solution thereof.
The reactants could be deposited as granules prepared as described above
in the preparation of tablets and capsules, but of extremely small size,
e.g. passing through a No. 100 sieve. The mixture of granules is deposited
on the carrier particles by mixing therewith in reactant:carrier
proportions of about 1:1 to 1:10. Carrier particles may be natural or
synthetic, organic or inorganic. Preferred are lactose crystals, pollen
grains, spores, starch grains (preferably rice), and the like. For
delivery as a dry powder, any commercially available inhaler may be used
such as the Tribohaler and Spinhaler, for delivering the powder in
pulse-dosage amounts. According to another inhalation method, an amount of
mixture of reactant granules on carrier particles containing sodium
nitrite and ferrous sulfate in a weight ratio of about 1:4 per dose, is
charged into a pressurized aerosol container with sufficient propellant,
e.g. Propellant (Freon) 12, to provide the desired number of doses or
individual sprays. The inhaled reactant carrier granule particles produce
NO in situ in the respiratory tract and lungs by contact with body
moisture.
Examples (formulations) 11 and 12 illustrate procedures and materials for
preparing inhalation means according to the invention.
EXAMPLE A
For the constant rate delivery of NO to a desired situs in the body of a
sentient animal, it is preferred to employ the known osmotic pump
technology. The osmotic pump itself is a rigid or flexible container in
the form of a bag, sleeve, sac, can or the like made with a semipermeable
membrane or coating, e.g. cellulose triacetate, permitting passage there
through of water into the interior of the container into which material to
be administered is charged. (Osmotic pump systems are commercially
available for example from the ALZA Corporation, Palo Alto, Calif. The
container is connected and opens into tubing, rigid or flexible, of metal,
e.g., steel, or plastic, e.g. polyethylene, leading to the desired
treatment situs.
Using for example ALZA's osmotic pump model Alzet 2001 (two are required),
the first pump is filled with 1M. aqueous ferrous sulfate, if desired with
an equivalent amount of citric acid, and the second pump is filled with 1M
aqueous sodium nitrite. The two pumps are each connected through tubing to
a common cannula catheter, e.g. stainless steel, in which the two aqueous
reactant solutions are mixed and production of NO begins. The catheter
assembly is connected through tubing to the desired treatment situs in the
body of the animal through which tubing NO and mixed reactant solutions
are fed to said situs. The capacity of the reservoir of this pump model is
200 microliter, the pumping rate of NO is 1 microliter per hour and the
duration of the pumping is 1 week. The delivery of NO is initiated when
the filled pumps are implanted in the animal body or placed in aqueous
physiological solution (water) outside the body.
Using for example ALZA's pumps model Alzet 2ML4 charged with the same
reactant solutions, (the capacity of this model is 2 ml.), the delivery
rate of NO is 2.5 microlitres per hour for 4 weeks. The amount, rate and
duration of NO delivery is programmed and controlled by proper choice of
the pump (capacity, type and thickness of semipermeable membrane, etc.)
and the concentration of the reactants. Temperature also affects the rate
at which water crosses the semipermeable membrane and enters the osmotic
sleeve, pump or container, and consequently the in vitro and in vivo
pumping rate of the pumps (which varies directly with the temperature).
The following further examples and formulations are only illustrative of
preferred embodiments of this invention and are not to be regarded as
limitative. All amounts and proportions set forth herein and in the
appended claims are by weight, and temperatures are in degrees C. unless
otherwise indicated. In the examples, PVP (polyvinyl pyrrolidone) is
employed in the form of a 10% solution in ethanol. The PVP has a MW of
about 40,000, K value of 10-18 (intrinsic viscosity) although products of
30,000-150,000 MW or more may be employed.
EXAMPLE (Formulation) 1
Tablet Providing 0.36 mM NO
______________________________________
mg
______________________________________
ferrous sulfate 100
citric acid 30
sodium nitrite 25
mannitol 85
polyvinylprrolidone (PVP)*
5
polyethylene glycol 6000 (PEG)
5
total weight per tablet
250 mg.
______________________________________
*as 10% solution in ethanol
EXAMPLE (Formulation) 2
Tablet 0.036 mM NO
______________________________________
mg.
______________________________________
ferrous sulfate 10
citric acid 3
sodium nitrite 2.5
mannitol 38.5
PVP 1
PEG 6000 3
total weight 58 mg.
______________________________________
The tablets of Examples 1 and 2 are prepared as follows
1--Ferrous sulfate, citric acid, and half of the mannitol are pulverized
and screened from sieve No. 40
2--The powder mix is granulated with half the 10% PVP in ethanol and dried
at 60.degree. C. for 12 hours in hot air oven.
3--The dried granules are passed through sieve No. 60
4--Sodium nitrite and the rest of mannitol are granulated the same way with
the rest of the 10% PVP in ethanol, and the granules dried at 60.degree.
C. for the same period of time, then passed through No. 60 sieve.
5--The first granules and second granules are mixed with PEG 6000 (PEG 6000
acts as lubricant and anti-adhesive) and compressed into tablets.
6--The tablets obtained dissolve completely within 12-15 min. in water
liberating NO gas as effervescent tablets.
EXAMPLE (Formulation) 3
Capsule 0.36 mM NO
______________________________________
mg
______________________________________
ferrous sulfate 100
citric acid 30
sodium nitrite 25
lactose 72
PVP 4
total weight 231 mg
______________________________________
EXAMPLE (Formulation) 4
Capsule 0.036 mM NO
______________________________________
mg
______________________________________
ferrous sulfate 10
citric acid 3
sodium nitrite 2.5
lactose 211.5
PVP 4
total weight 231 mg
______________________________________
The capsules of Examples 3 and 4 are prepared as follows:
1--Ferrous sulfate, citric acid and half of the lactose are pulverized and
screened from sieve No. 40
2--The powder mix is granulated with one half the 10% PVP in ethanol and
then dried at 60.degree. C. for 12 hours.
3--The dried granules are passed through sieve No. 60
4--sodium nitrite and the rest of lactose are granulated the same way with
the rest of the 10% PVP in ethanol and the granules dried at 60.degree. C.
for 12 hours and then passed through sieve No. 60
5--The first and second granules are mixed thoroughly and used for the
filling of hard gelatin capsules (Size No. 2)
6--The filled gelatin capsules disintegrate in water, and liberate NO in 10
min.
EXAMPLE (Formulation) 5
Enteric Coating
The tablets and capsules of Examples 1-4 are coated enterically with the
following formulation in order to liberate NO in the intestine. The
enteric coated tablets and capsules resist disintegration in artificial
gastric juice for 2 hours, but when placed in artificial intestinal juice
they disintegrate in 20 min.
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grams.
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CAP* 120
propylene glycol
30
Span** 10
ethanol 450
acetone 1000
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*Cellulose acetate phthalate film former
**Sorbitan monolaurate wetting agent
EXAMPLE (Formulation) 6
Ointment 0.018 mM Nitric Oxide/g.Ointment
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mg
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ferrous sulfate 10
citric acid 3
sodium nitrite 2.5
lactose 20
PVP 1
hydrophilic base* 1936
total weight 2000 mg
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*PEG 300:400 in 2:3 ratio
EXAMPLE (Formulation) 7
Ointment 0.18 mM Nitric Oxide/g.Ointment
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mg
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ferrous sulfate 100
citric acid 30
sodium nitrite 25
lactose 200
PVP 10
hydrophilic base* 1635
total weight 2000 mg
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*As in Example 6
EXAMPLE (Formulation) 8
Suppository
For the delivery of nitric oxide in suppository form, the above
formulations of Examples 6 and 7, except for change of the hydrophilic
base to PEG 4,000:400 in 2:1 ratio, are shaped into suppositories.
The ointments and suppository of Examples 6-8 are prepared first by
granulation as described above for the tablets of Examples 1 and 2 using
lactose instead of mannitol and the indicated hydrophilic base mixtures of
PEG 4,000 and 400 instead of the PEG 6,000 mold lubricant and
anti-adhesive or release agent.
EXAMPLE 9
Transdermal Patch
For the transdermal delivery of NO to a situs on the animal skin, a
pressure sensitive patch or laminate of an inert foraminous or porous
inert cellulose matrix is impregnated with ferrous sulfate solution in an
amount or rate of 0.025 mM/square cm. and covered with an outer water
resistant foil web. The patch is activated by treatment with 50
microlitres of sodium nitrite solution in water (1M) and immediately
applied to the skin where NO gas is released in situ.
EXAMPLE 10
Transdermal Patch
Example 9 is repeated except that the ferrous sulfate is impregnated in an
amount or rate of 0.050 mM/square cm. and the activation is with 100
microlitres of the sodium nitrite solution.
EXAMPLE (Formulation) 11
Dry Powder Inhalation
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mg.
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ferrous sulfate 10
citric acid 3
sodium nitrite 2.5
PVP 0.4
micronized lactose (10 micrometer av. particle size)
10.1
Total Weight per dose 25 mg
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1. Granulate the ferrous sulfate and citric acid with one-half the PVP (0.2
mg), dry at 60.degree. C. for 12 hours in vacuum and pass the granules
through No. 100 Sieve.
2. Granulate the sodium nitrite with the remaining PVP, then dry and sieve
the same way.
3. Mix the granules from steps 1 and 2 with the lactose. Particle size of
the powder mix should not exceed 120 micrometers.
The resulting powder mix is charged into a Turbohaler or Spinhaler and
expelled into the respiratory tract and lungs at 25 mg. per dose or spray.
Liberation of NO is initiated and released in situ by contact of the
powder mix with body moisture.
EXAMPLE (Formulation) 12
Aerosol Metered Dose Inhaler
1. Preparation of 20% Ferrous Sulfate on Pollen.
Add 4,000 mg deproteinized pollen to 10 ml. of a 10% solution of ferrous
sulfate in water (1,000 mg), mix 10 minutes, dry slowly under vacuum at
50.degree. C. and mix after drying.
2. Preparation of 10% Sodium Nitrite on Pollen.
Add 4,500 mg. deproteinized pollen to 10 ml. of a 5% solution of sodium
nitrite in water (500 mg.), mix 10 minutes, dry slowly under vacuum at
50.degree. C. and mix after drying.
3. Preparation of NO Metered Dose Inhaler
Mix 400 mg. of the ferrous sulfate-loaded pollen from step 1 with 200 mg of
the sodium nitrite-loaded pollen from step 2, charge the blend into
aerosol cans, then add 10 ml. of Propellant 12 (pressurized filling) to
provide 100 doses (1 dose=0.10 ml, 100 doses=10 ml.). One dose or spray
contains 0.20 mg. of sodium nitrite and 0.80 mg. of ferrous sulfate.
Liberation of NO is initiated and released in situ by contact of the spray
with body moisture in the respiratory tract and lungs.
Instead of pollen, rice starch grains or spores can be used.
This invention has been disclosed with respect to preferred embodiments and
it will be understood that modifications and variations thereof obvious to
those skilled in the art are to be included within the spirit and purview
of this application and the scope of the appended claims.
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